The sales of printed books and magazines in a bookstore are usually boosted by being sold as a supplement together with various goods. On the other hand, there is a case where an ebook and its additional book content as a supplement are sold as a single book. Such a sales strategy is differentiated from that of printed books.
As a supplement of an ebook, for example, extra content of an ebook is provided, and a free gift is prepared in liaison with a goods-selling website and shipped later. Currently, it is possible to provide only a supplement that can be output and processed in a device with which to browse an ebook. It is desirable to make another device output and process second content (for example, supplement of ebook) acquired based on first content (for example, ebook).